Retro Game of the Day! Gradius
Yesirree - today's game is the great Gradius by Konami, released originally (arcade) in 1985 and ported a year later to NES and a good slew of other platforms. And still going strong! Some of you may remember this game under the title "Nemesis."
And so, here we have the game that really popularized the whole "collect powerups to increase your arsenal" in videogaming. I am not sure if it was the very first to have any level of a powered-up shot, but it's certainly the one which did it most notably to begin with.
A standard horizontal shooter, and a fairly colorful one for its time, you would kill waves of enemies - certain foes would leave behind a "powerchip" in their wake, if you grabbed it you would increment a meter at the bottom of the screen. When you collected enough you could activate a powerup of your choosing (speed up at the low-end, options, shields, alternate weapons). On that note, the "invincible options" that shadow your ship (and showed up in many similar games) also can trace their origins here, though I would be interested to see if they showed up in some obscure game previously.
Gradius followed a long line of similarly-presented shooters, one of the more notable efforts being Konami's own Scramble (to which this game can directly trace its lineage). This title upgraded the general presentation of this sort of game, with an end boss waiting at each level's conclusion (often with their own "power bars" which must first be shot away at, to reach their core weakspots). The graphics and sound FX were also a noticeable upgrade from what many other scrolling-space shooters looked like in those days.
Gradius is a fairly lean game by today's standards, though still difficult and certainly very playable. It can easily be considered one of the most renowned games of all time, which has left a very notable impression on the entire gaming landscape. Its legacy is long and we will still see games bearing it's namesake, and play style, for years to come, even if it has been out of fashion for generations.